Blood Cardiovascular System - 1
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Transcript of Blood Cardiovascular System - 1
BloodCardiovascular System - 1
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FUNCTIONS of BLOOD • transports substances & maintains
homeostasis in the body
Hemo = blood• hemophobia: fear of blood• hemostasis: bleeding is under control• hematocyte: blood cell• hematemesis: vomiting blood• hematuria: bloody urine• hematopoiesis: formation of blood
cells
Blood• is a type of CT made up of scattered
cells & a liquid matrix
What’s in blood?1. Cells (45%)– RBCs– WBCs– Platelets (plts)
2. Plasma (55%)– water, a.a., proteins, carbohydrates,
lipids, vitamins, hormones, electrolytes, cellular waste
Hematocrit• vol of blood cells in a sample of blood• blood centrifuged then % cells
figured• normal levels:– Newborns: 55-68%– 10 yr olds: 36-40%–Women: 38-46%–Men: 42-54%
RBCs• erythrocytes, hematocytes, corpuscles– formed in bone marrow
• shape: biconcave disc– allows for optimal surface area for
diffusion of O2 & CO2
• 5 million/mm3• no nucleus– so no cell division
• live about 120 days– then phagocytosed in liver & spleen
RBCs Functions1. transport O2 thru out body (lungs
cells)– hemoglobin: (hgb) large protein that O2
attaches to inside RBC2. transports CO2 thru out body (cells
lungs)
Hemoglobin • oxyhemoglobin: plenty of oxygen
being carried in RBCs, blood is bright red
• deoxyhemoglobin: not carrying much oxygen, blood is burgundy-red
Iron• critical element needed to make hgb
& normal RBCs• most of body’s Fe is in RBCs– in heme portion
Erythropoietin • hormone secreted by kidneys
stimulates formation of more RBCs by bone marrow– requires: vit B12 & Folic Acid
White Blood Cells (WBCs)• leukocytes• general function: defend the body
against pathogens
White Blood CellsType Name Function Picture
Granulocytes Neutrophils aka
PMNspolymorpho-neutrophils
very active in phagocyting bacteria &
are present in large #s in pus of wounds, most common of all types,
normal= 60% of WBCs
(granular cytoplasm)
Eosinophils attack parasites, control allergic reactions2% of WBC count
White Blood Cellstype Name Function Picture
Granulocytes continued
Basophils produces heparin (prevents blood clots) &
histamines (inflammatory reaction)
1% of WBCAgranulaocytes (lacking granular cytoplasm)
Monocytes precursors of macrophages;
6% of WBC
Lymphocytes main cell of immune system
30% of WBC
Platelets (plts)• thrombocytes• cell fragments formed from
megakaryocyte, live ~4 days• help initiate formation of blood clots– release clotting factors
Plasma • 92% water• Functions:– transport nutrients, gases, vitamins,
hormones–maintain fluid & electrolyte balance–maintains normal pH
Plasma Proteins1. Albumins– made in liver– maintain osmotic pressure & blood vol.
2. Globulins– α & β, from liver– transport lipids & fat-soluble vitamins
3. Fibrinogen – from liver, largest of plasma proteins– in blood clotting fibrin
Hemostasis • process of stopping bleeding1. blood vessel spasm– damaged vessel smooth muscle to
contract slows or stops blood loss– plts release serotonin (vasoconstrictor)
2. plt plug forms– plts become sticky forming plug over
damaged area3. Coagulation– forms hematoma/fibrinogen fibrin
Coagulation • when tissue damaged damaged
cells release prothrombin activator (with Ca++)
• prothrombin thrombin• thrombin acts as enzyme to cause
fibrinogen fibrin• fibrin traps plts & RBCs to form
hematoma (blood clot w/in vessel)